Revealing the Imperceptible

It’s midterm season, which means that your heart has likely raced through at least one tough math problem or puzzling Ec10 question during the past few weeks. For most people, the only way to know this would be to physically take your pulse. But what if someone could actually see your rushing heartbeat, displayed in vivid color on your face? Scientists at MIT’s Computer Science and Artificial Intelligence Laboratory recently devised a way to do just that, by amplifying subtle changes in the color or motion of video footage.

The program, called Eulerian Video Magnification, works by analyzing video sequences on the pixel level. First it decomposes the video input into bands of different spatial frequency, and then applies a temporal filter to identify the bands of interest. Finally, these signals are magnified by a specified factor and added back into the original video frames.

In other words, by tracking and amplifying the imperceptible flush of blood in your face each time your heart beats, the program could transform a simple video to make you appear to turn crimson in conjunction with your pulse. Talk about school spirit.

Of course, the algorithm has many other more practical applications. It was initially created to help monitor the vital signs of newborns, but Professor William T. Freeman and the rest of the team have since brainstormed countless potential uses, from search-and-rescue and lie detection, to safeguarding in construction and engineering. Now you can even come up with your own, by uploading a video and applying the program at this site (thanks to Quanta Research Cambridge).